I would avoid IFTTT, it is ok for use as a demo or toys, but the latency and unreliability for a production or mission-critical system is questionable.
Bear in mind it is a free service, so there is no incentive for good customer support or longevity. They might be buried under the weight of their own popularity.
Personally, Siri has been disappointing, I have had much more success with Amazon Echo/Alexa (I have both Siri and Echos). There is such a huge difference in having a voice command system that doesn’t require having an iPhone and taking it out of your pocket.
My wife and other family members hate using Siri but have taken to Alexa “organically”. They watched me use it and started talking to it on their own, imitating my voice commands, without my having to nudge them or instruct them in how to use it.
Alexa is also “platform neutral” because you don’t have to have an IPhone, so Android, Windows Phone, Blackberry, and non-phone users are not left out.
I would suggest anyone working on plug-ins or integrations take at look at the Echo. Right now, it is the most popular voice control and “Multi-product automation hub”. (Yeah, Google has an Echo clone coming out later this year, but nobody knows if it will be a dud like many of their other hardware products or a contender – too early to bet on that yet.)